Performance evaluation of the Helena V8 capillary electrophoresis system.

OBJECTIVES: To compare the performance characteristics of the Helena V8® and Sebia CAPILLARYS2® automated capillary electrophoresis systems to agarose gel serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE) using the Helena SPIFE3000®. DESIGN AND METHODS: Serum protein electrophoresis and immunosubtraction was performed on 100 consecutive patient samples comparing two capillary-electrophoresis platforms with agarose-gel SPE and IFE; IFE was used as the gold standard. Chart review was performed on patients where results were discordant between methods. Analytical precision was determined using Sebia's normal and abnormal controls. RESULTS: The sensitivities of the CAPILLARYS2, V8, and SPIFE3000 agarose gel for identification of monoclonal gammopathies were respectively 97.4 (95%CI 91.1-100), 92.3 (95%CI 82.2-100), and 89.9 (95%CI 79.1-97.6). The specificities of the CAPILLARYS2, V8, and SPIFE3000 agarose gel were respectively 57.6 (95%CI 45.0-70.2), 72.2 (95%CI 61.0-83.3), and 75.4 (95%CI 60-82.8). These analytical performance characteristics were statistically equivalent between systems (P>0.05). The analytical precision of the capillary-based methods was also statistically equivalent. Chart review of available data from discordant samples revealed that 7/10 patients had a history of multiple myeloma or known monoclonal gammopathy and were being treated or monitored. All discordant samples had low concentration monoclonal proteins (<0.3g/dL). Both capillary-based methods performed poorly (collectively <50% accuracy) at detecting low concentration non-IgG antibodies (IgA, IgM, and light chain monoclonal gammopathies) compared to IFE. CONCLUSIONS: The Helena V8 and Sebia CAPILLARYS2 were analytically equivalent to the SIFE3000 for identification of IgG monoclonal gammopathies >0.3g/dL. Interpreters using the automated immunotyping/immunosubstraction systems performed poorly at detecting low concentration and non-IgG monoclonal gammopathies.

Duke Scholars

Author Jessica Lynne Poisson Pathology